This invention relates to an improvement in securing or chucking, in a system for separating and irradiating multi-component fluids and, in particular, to the use of such systems in the field of treating cells with photoactivatable compounds by radiation, which activates the compounds to effect cellular change.
Numerous human disease states of the body respond favorably to the treatment of selected bodily fluid components, such as those found in blood, by visible or ultraviolet light irradiation Such treatment may be effective to eliminate immunogenicity in cells, inactive or kill selected cells, inactivate viruses or bacteria, or activate desirable immune responses. Certain forms of treatment with light irradiation may be effective without the introduction of outside agents or compounds, while others may involve the introduction of specific agents or catalysts. Among the latter treatment techniques is the use of photoactivatable agents to regulate the population of leukocytes. It is well-known that a number of human disease states may be characterized by the over production of certain types of leukocytes, including lymphocytes, in comparison to other populations of cells which normally comprise whole blood. Excessive or abnormal lymphocyte populations result in numerous adverse effects in patients including the functional impairment of bodily organs, leukocyte mediated autoimmune diseases and leukemia related disorders many of which often ultimately result in fatality.
U.S. Pat. Nos. 4,321,919; 4,398,906; 4,428,744 and 4,464,166 to Edelson describe methods for treating blood whereby the operation or viability of certain cellular population may be moderated thereby providing relief for these patients. In general, the methods comprise treating the blood with a dissolved photactivatable drug, such as psoralen, which is capable of forming photoaducts with DNA in the presence of ultraviolet (U.V.) radiation. It is believed that covalent bonding results between the psoralen and the lymphocyte nucleic acid thereby effecting metabolic inhibition of the treated cells. Following extracorporeal irradiation, the cells are returned to the patient where they are thought to be cleared by natural processes but at an accelerated pace, believed attributable to disruption of membrane integrity, alteration of DNA within the cell, or like conditions often associated with substantial loss of cellular effectiveness or viability.
Although a number of photoactivatable compounds in the psoralen class are known, 8-methoxy psoralen is presently the compound of choice. An effective radiation for this compound, and for many psoralens in general, is the ultraviolet spectrum in the range of approximately 320 to 400 nanometers, alternatively referred to as the uvA spectrum. As the development of photoactivatable compounds proceeds, it may be expected that changes in the preferred activation radiation spectrum may occur. For instance, it may be preferable to treat some disease states with light in the ultraviolet spectrum of 280 to 320 nanometers, referred to as the uvB spectrum.
An apparatus for carrying out the above referenced Edelson method of treatment is described in detail in U.S. Pat. No. 4,921,473 to Lee et al. This document describes in detail a multi-component bodily fluid separating and irradiation system which includes a housing, a rotatable chuck located within the housing, a removable separation/irradiation chamber suitable for mounting in the rotatable chuck which has at least one passage way for the passing of a multi-component bodily fluid into and out of the rotatable chamber, and a source radiant energy connected to the housing and located near the separation irradiation chamber so as to allow transmission of radiant energy to the interior of the chamber that contains the multi-component bodily fluid.
While the foregoing system and method has met clinical and regulatory standards, it is desirable to provide the system with greater operational efficiency.
In particular, the current system for retaining the removable separation/irradiation chamber utilizes either screws, which are subject to over- or under-tightening with each use, along with O-rings for gripping when the screws are tightened. In addition to problems with the tightening of the screws, the O-rings present an additional problem that make it difficult to insert or release the centrifuge bowl unless the O-rings are regularly cleaned and frequently greased.
Another method for retaining the bowl is the use of wedges. Wedges however, can be misplaced and lost and also present the possibility of being improperly inserted.
Finally, vacuum systems are available to retain the removable chamber while it is being rotated during use. Although vacuum systems are convenient, they are fairly complicated requiring pumps and rotating seals. In addition, this type of system has components that can be contaminated by a spill and is difficult to clean.
It is an object therefore, of the present invention to provide a system for automatically securing a removable chamber inside a rotating chuck that does not require operator adjustment.
It is another object of the present invention to provide such a securing system that does not have parts that can be misplaced and lost.
It is another object of the present invention to provide such a securing system that is simple, does not require additional active mechanical components and does not require cleaning or maintenance.